The tax reform law enacted in late 2017 is already threatening to exacerbate the affordable housing crisis. The law is expected to eliminate 300,000 affordable housing units over 10 years, partly because it will reduce the value of banks' low-income tax credits, which finance half of all affordable housing units, according to a report by the nonprofit real estate firm NHP Foundation. Lowering the corporate tax rate reduces the value of the tax credits by roughly 15% because banks and partnerships that use the tax credits are limited in deductions on appreciating expenses.